Recent advances in synthetic fiber ropes will greatly influence the practice of civil engineering in the oceans during the 21st Century. New fibers have moduli almost as high as steel and are stronger than steel. Fiber ropes are light weight and easy to handle. They do not corrode. New rope and mooring system designs can compensate for the inferior wear properties of fibers and take full advantage of the other fiber properties. Some fiber ropes have tension and bending fatigue performance superior to those of wire ropes. The newer forms of fiber ropes are thus ideal for many ocean engineering applications.